If you have ever found that after updating an app on your Android device that bugs are causing it to function incorrectly and want to revert back to a previous version of the app then AppDowner could be the app to make the task a little easier.
Reverting to a previous version of an app can cause a loss of data if you uninstall the app so XDA user pyler has created an app that allows you to downgrade without having to uninstall and thereby not causing a loss of data.
The app has a simple interface with the two options that are needed to complete the task of reverting to a previous app. Select APK allows you to find the APK you wish to install and Install APK, obviously, installs the APK. Once those two steps are completed you will have downgraded to whichever version you chose.